[libvirt] problems with <seclabel> when restarting libvirtd

I had libvirtd build from 0.9.2+something running on my test machine.
There was a single guest running on it.

I grabbed the latest libvirt from git (0.9.3+??), built an rpm, and
installed it. My guest reconnected with no problems, but I was unable to
start new guests due to an selinux problem with the labeling of the
image file. Interestingly, I found that I could shutdown and restart the
one guest that had been running at the time of the upgrade. *Until* I
restarted libvirtd again while the guest was stopped. After this point,
I could no longer start that guest either.

I then set selinux to permissive mode and was able to start my original
guest. Then I restarted libvirtd and found that, although the qemu-kvm
process was still running, libvirtd couldn't reconnect to the guest.
When I looked at the logs, I saw this: